Riccardo Pascotto, T-Nova Deutsche Telekom Innovationsgesellschaft mbH Berkom, (email removed)AMASE investigates techniques and solutions for enhancing an existing agent platform in order to support stationary and mobile agents in a wireless-mobile communication environment. This provides access to Multimedia Information Services by agent-based mobiles. AMASE enables a high degree of user mobility between various networks, devices, and physical locations. The main focus of the project is on small and mobile devices, such as a portable PC or Personal Digital Assistant.
Figure 1: The AMASE overview The objectives of AMASE are to:
To reach those goals the Siemens SWARM system is used.
The key issues addressed by AMASE are the scalable agent platform, network adaptation, mobile operation, secure agent, customisable agents, and agent support. Each of these involve extensive investigation, development and validation.
The scaleable agent platform covers a number of issues. The operation of agent platforms need to be optimised according to the system resources available on various device platforms, such as memory, processor speed and power budget, etc. The agent environment must be supported, simultaneously, from as many networks that are accessible from the device platform. Furthermore, the agent environment software architecture must be flexible and modular, so as to support various degrees of functional richness - such as the number of networks and telecommunications services supported by a device platform. A scheme has to be developed that enables the agent platform to deal with potential overload conditions caused by visiting agents and events arising from, for example, available resources & capabilities, and refusal & replacement policies. There is also a need to develop a minimal agent platform core that can fit handheld devices.
Network adaptation refers to enhancing the agent environment so that it adapts to the quality of service of the accessed network, in terms of (e.g.) bandwidth and delay. The agent environment must also support operation over sporadic wireless connections in the context of operation atomicity and recovery.
Regarding mobile operation, there needs to be a scheme of operations for the agent environment that supports seamless operation and recovery when the device moves between networks. In the event of unrecoverable communication operations in the agent environment, there needs to be a notification scheme for agent operation failure that supports agent-originated recovery. Agent platform APIs will give agents access to geographical location information.
Secure agent execution is a concept that applies existing security mechanisms to agent communications in order to solve traditional security problems. These include: authentication, authorisation, confidentiality, integrity, non-repudiation, and protection against malicious agent systems.
Customisable agents are needed in order to adapt agents to the application environment and user's needs. Basic development tools are needed to create and integrate agents into agent-based applications. Appropriate agent structures and agent execution models have to be developed that enable agent code and data to be updated easily. Appropriate communication languages for typical applications have to be investigated.
Agent support incorporates network-independent access to specific telecommunications services, such as fax and SMS, into agent platform APIs; these are used in agent-based applications. Agent support also includes the provision of directory services that can be used to register or reference agents and services, independently of particular directory technologies.AMASE has developed a generic open communication platform based on agent technology. The Java-based AMASE agent system was used to set up an agent environment for agent-based applications, the main focus being to enable users of mobile handheld devices to access value-added services over wireless networks. This open communication environment allows service providers to create application-specific, customisable and adaptive services that can be easily adapted to meet new requirements.
The AMASE agent platform may be installed on server machines, desktops and mobile devices running Java or Personal Java. For instance, the AMASE system was successfully ported to the EPOC32 simulator for the PSION5 palmtop. While the base software is the same for servers and desktops, it is different for a mobile device like a PDA because of the device inherent resource constraints.
Figure 2: The agent environment
In addition to agent platforms, external services may be integrated into an agent environment thus enabling agents to communicate with systems outside of the agent environment. The AMASE Primary Telecommunication Services agent package demonstrates how this can be used to give agents access to existing telecommunication services such as SMS or Fax. Figure 2 shows an example of the AMASE agent environment.
Figure 3: The AMASE system architecture
The administrative part of the Agent API can start mobile agents, monitor their behaviour and stop their execution. An agent platform can provide additional services over and above that of the Agent API. For instance, there may be specialised agent services or access to external services, and these are encapsulated by a system agent (SA) - a privileged agent that is usually loaded at start-up of the agent system. It executes in the security context of the agent system owner, which requires access to system resources such the file system, communication lines, etc. The agent system, itself, communicates locally with a service centre that offers information about services available locally or distributed across the entire agent environment. It supports service-oriented trading and comprises an agent directory that supports (e.g.) agent tracking.
The Communication Facilities (CF) is a generic component that provides support in a wireless environment. Its functionality can be sub-divided into three categories:
The AMASE project introduced the concept of an agent package - a set of agent classes required to perform a specific task. These include classes for both mobile agents and system agents, and thus an agent package can be thought of as the conceptual equivalent of a programming language module (e.g. a Java package) in the agent world.
Mobile agent-based access to real-life value-added banking services was implemented to demonstrate the feasibility of the AMASE approach for commercial applications. The associated AMASE application addresses three fundamental aspects of the service paradigm: service configuration, service access, and service-triggered notification. In the context of the project the Alpha Credit Bank in Greece granted the project members access to the Alphaline home-banking services which could be accessed via APIs of a dedicated server. It allows customised client applications to invoke the basic Alphaline banking services, and the used agent paradigm allows for rapid introduction of new services to the user.
The architecture of the AMASE application is partitioned in two systems: the External Banking System and the AMASE Agent Environment. There are also two management domains: the Banking Domain and the User Domain. Figure 4 depicts the agent-based architecture for the case where a single user interacts with the application.
Figure 4: Architecture of the AMASE application
The demonstrator was designed to give special attention to user mobility, disconnected operation, user reachability, and automated notification. The implemented services are context-aware, and use information contained in user profiles and supporting databases to locate currently used terminals and users at their respective geo location. Before migrating to the user, agents have to specify their migration policy. This includes negotiation of the resources needed on the destination platform/device. Furthermore, agents are able to behave according to the currently provided network QoS by using different interaction schemes with the mobile user.
Three agent-based value-added banking services provide realistic evaluation of the service and the technology:
The AMASE approach demonstrates access to real-life banking services and, although no standardised agent system is used, it is expected to have an impact on the standardisation activities within OMG MASIF. Furthermore, compliance and integration of the WAP standard are exploited, and AMASE's approach has been to evaluate results to provide recommendations for the WAP and OMG MASIF standardisation activities.
In summary, AMASE contributes to the general ACTS/IST-programme objectives of user-friendliness, accessibility, convergence and quality of services of the Information Society for scalable agent-based mobile access to Multimedia Information Services.ACTS AMASE project homepage, http://b5www.berkom.de/AMASE
'AlphaDirect Server - Programmer's Guide', Alpha Credit Bank
Björn Schiemann, Birgit Kreller, Matthias Reich, Ernö Kovacs, Klaus Röhrle, Hong-Yon Lach, Anthony Sang-Bum Park, Steffen Lipperts: 'Agent Environment Specification - Part B', AC346 - ACTS Project, Deliverable 01b, 1998.
Domique Carrega, Björn Schiemann, Dana Trifanescu, et al.: 'Delivering Value-Added Banking Services for Mobile Customers with the AMASE Agent Environment'; Proceedings of the ACTS Mobile Summit, Sorrento, Italy, June 8-11,1999.
Björn Schiemann, Ernö Kovacs, Klaus Röhrle: Adaptive Mobile Access to Context-Aware Services; Proceedings of the 3rd International Workshop on Mobile Agents, Palm Springs, USA, October 1999
Björn Schiemann, Ernö Kovacs, Riccardo Pascotto: Giving Mobile Users Access to Net-Based Services - A Mobile Agent Approach Adaptive; 4th International Distributed Conference 1999, Madrid, Spain, September 1999
The next section of this document: CAMELEON: Communication Agents for Mobility Enhancements in a Logical Environment of Open Networks